The instant invention relates to pipe couplings and more particularly to a pipe coupling which is operative for rigidly securing a pair of grooved pipe sections together in closely spaced, substantially aligned relation.
Pipe couplings of the general type which are receivable in engagement in annular grooves adjacent the ends of pairs of pipe sections for securing the pipe sections together have been heretofore available for many years; and in this regard, the devices disclosed in the U.S. Pat. Nos. to FLYNN, #1,978,453; PIATEK, #3,054,629; SHORT, #3,251,615; and BEUKEMA, #4,408,788, are exemplary of pipe couplings of this general type. However, while couplings of this general type have been found to be capable for effecting connections between the adjacent ends of pairs of pipe sections, they have generally only been operative for effecting flexible connections wherein slight amounts of both axial and lateral or bending movement, as well as slight amounts of rotational movement, are possible between connected pipe sections. In this regard, it has been found that in many cases slight degrees of flexibility between connected pipe sections can be tolerated without adverse effects, and that in certain applications, slight degrees of flexibility may even be desirable. However, more recently, it has been found that substantially rigid connections between pipe sections are preferable for certain types of piping systems and, therefore, a need has developed for a pipe coupling which can be effectively utilized for rigidly securing the adjacent ends of a pair of grooved pipe sections together in substantially aligned relation.
The coupling disclosed in the U.S. Pat. No. to RUNG et al, #4,611,839, is generally operative for providing a substantially more rigid connection between a pair of pipe sections; and it represents the closest prior art to the subject invention of which the applicant is aware. However, since the device disclosed in the U.S. Pat. No. to RUNG et al differs both conceptually and structurally from the coupling of the subject invention, it is believed to be only of general interest with respect thereto.
The instant invention provides a highly effective coupling which is adapted for rigidly securing the adjacent ends of a pair of grooved pipe sections together in substantially aligned relation. More specifically, the coupling construction of the instant invention comprises a plurality of coupling segments, each coupling segment including an arcuate main portion, a pair of apertured flanges extending outwardly from opposite ends of the main portion thereof and axially spaced first and second engagement means extending substantially radially inwardly from the main portion, and means for securing the coupling segments in encircling relation around a pair of pipe sections so that the engagement means of the coupling segments are received in the annular grooves in the pipe sections. The coupling segments are formed so that the apertures in adjacent flanges are offset from each other in a direction substantially parallel to the Z--Z axis of the coupling when the adjacent flanges are in substantially aligned relation, and the securing means are received in the apertures in adjacent flanges for first drawing the adjacent end flanges into offset positions wherein they are offset from each other in a direction substantially parallel to the Z--Z axis of the coupling and for then drawing the adjacent flanges together. When the coupling segments are secured on a pair of grooved pipe sections in this manner, opposite end portions of the engaging means of the coupling segments are urged against opposite side edges of the grooves in which they are received for rigidly securing the pipe sections together in substantially aligned relation. In this regard, the engaging means are preferably formed as spaced first and second inwardly extending ridges on the inner sides of the main portions of the coupling segments which are engageable with the side edges of the grooves. The coupling segments are preferably formed with end faces at the opposite ends thereof, and the end faces are preferably formed so that when the coupling segments are received in assembled relation, adjacent end faces are engageable and frictionally retained in nonslidable relation for retaining the adjacent ends of the coupling segments in offset relation. Further, the end faces are preferably formed so that they are engageable along planes which extend at acute angles to the Y-Z plane of the coupling and which are substantially perpendicular to the X-Z plane of the coupling, and the securing means perferably comprise threaded nut-and-bolt assemblies which are assembled through the apertures in adjacent flanges. Further, the end faces are oriented so that they cooperate to produce a wedging action which causes a stretching force to be applied to the securing means if a force is applied to the coupling which would tend to move the adjacent flanges back into alignment. The flanges are preferably formed with recesses therein on the sides thereof which face away from the adjacent flanges, the recesses preferably extending around the apertures in the flanges, and the nuts and the head portions of the bolts of the nut-and-bolt assemblies are received in the recesses to retain the head portions of the bolts and nuts in substantially stationary positions relative to the flanges as the nut-and-bolt assemblies are tightened to move the flanges into offset positions.
It has been found that the coupling of the instant invention can be effectively utilized for rigidly securing the adjacent ends of a pair of grooved pipe sections together in substantially aligned relation. In this regard, it has been found that because the apertures in adjacent flanges are in offset positions when the flanges are in substantially aligned relation, the nut-and-bolt assemblies of the coupling are effectively operative for first moving the flanges into offset positions wherein the apertures in adjacent flanges are in substantially aligned relation and for then drawing the flanges together. As a result, the ridges on the inner sides of the flanges are not only effectively drawn into engagement with the inner surfaces of the grooves in the pipe sections, but the opposite end portions of the ridges are normally urged into engagement with the opposite side edges of the grooves in order to rigidly secure the pipe sections together. In this regard, because the ridges engage both the inner surfaces and the side edges of the grooves, the coupling segments are effectively operative for resisting relative axial movement, as well as relative lateral or bending movement, and they also frictionally grasp the pipe sections to resist relative rotational movement. Further, once the fastening means have been tightened to secure the coupling segments on the pipe sections, the angular end faces of the coupling segments are frictionally retained in position and they are also operative with a wedging action which further resists relative movement between the opposite end faces of the coupling segments. More specifically, because the end faces of the coupling segments are disposed in angular planes, they are operative with a wedging action which causes stretching forces to be applied to the fastening bolts when forces are applied to the coupling segments which would tend to force the opposite end portions of the ridges away from the opposite side edges of the grooves. Hence, the angularly disposed end faces on the adjacent ends of the coupling segments cooperate to maintain the opposite end portions of the ridges in engagement with the opposite side edges of the grooves in the pipe sections.
Accordingly, it is a primary object of the instant invention to provide an effective coupling for rigidly securing the adjacent ends of a pair of grooved pipe sections together.
Another object of the instant invention is to provide an effective coupling comprising a plurality of coupling segments having spaced first and second radially extending ridges on the inner sides thereof which are engageable with the opposite side edges of the annular grooves in a pair of grooved pipe sections to rigidly secure the pipe sections together.
Another object of the instant invention is to provide a coupling comprising a plurality of arcuate coupling segments having apertured flanges adjacent the opposite ends thereof and fastening bolts which are receivable in the apertures in the flanges for drawing them together, wherein the apertures in adjacent flanges are in offset relation when the flanges are in aligned relation so that adjacent flanges are first moved into offset positions and then drawn together as the fastening bolts are tightened.
Other objects, features and advantages of the invention shall become apparent as the description thereof proceeds when considered in connection with the accompanying illustrative drawings.